鸟类鸣声具有物种识别、吸引配偶和守卫资源的作用，鸣声分化是繁殖前隔离的重要机制，对种内分化和物种进化起关键作用。鸣唱方言作为其产生的结果之一，长时间以来被认为是一种行为屏障，阻碍各方言区种群间的交流和基因流动。但近期研究得出了相冲突的混合结果，发现很多鸟种的方言并不能形成有效的阻隔。白头鹎是我国长江以南广泛分布的常见留居型鸣禽，近期迅速向北扩张，前期研究发现整个北方新建殖民种群已经发展出3个明显的鸣唱方言区，现怀疑目前的不同鸣唱方言是否引起交流障碍，形成屏障作用。本项目从量化比较3个方言区间的声学差异入手，通过鸣声回放实验检验不同方言能否彼此识别，明确白头鹎新建殖民种群之间是否存在鸣声行为隔离。在当前的微进化尺度上，为白头鹎近期迅速扩张之后种内水平的快速分化和进化提供行为学证据；从鸣声分化角度探寻种内分化的机制，揭示鸣唱方言在鸟类繁殖分化和物种形成过程中的屏障作用。

Birdsongs have functions in species recognition, mate attraction and territory defense. As an important mechanism of isolation before breeding, vocal divergence plays a key effect in intraspecific divergence and species evolution. Song dialect is one evolutionary result of vocal divergence and has been long considered as a behavioral barrier, which hinder communication and gene flow among populations. However, recent researches got conflicting results and found existence of gene exchanges among dialectal populations. Light-vented Bulbul Pycnonotus sinensis is a common resident songbird of southern China and has been expanding northward since 1930s. Former researches found that the northern colonial populations had already developed 3 song dialect regions, and these dialects might be communicative barriers among different dialectal regions. This project will investigate acoustic divergences quantitively among dialect religions and conduct playback experiments to test whether different dialect populations can recognition each other and to exam if there any behavioral isolation has already formed. The result can provide behavioral evidence for rapid divergence and evolution of Pycnonotus sinensis after recent range expansion on the present microevolutionary scale, and can uncover barrier effect of song dialect in breeding divergence and species evolution process from intraspecific vocal divergence point.